Information display device

Abstract

In an information display device, a touch panel is provided in front of a display part and detects a drag operation. A function execution unit executes a predetermined function according to the drag operation. A touched-point number determination unit determines the number of touched points in the drag operation detected by the touch panel. A function control unit changes a control parameter of the predetermined function to be executed by the function execution unit according to the number of touched points determined by the touched-point number determination unit.

1 . An information display device, comprising:
 a display part for displaying an image;   a touch panel provided in front of the display part for detecting a drag operation;   a function execution unit for executing a predetermined function according to the drag operation;   a touched-point number determination unit for determining a number of touched points in the drag operation detected by the touch panel; and   a function control unit for changing a control parameter of the predetermined function to be executed by the function execution unit according to the number of touched points determined by the touched-point number determination unit.   
     
     
         2 . The information display device according to  claim 1 , wherein
 the predetermined function is a scroll function which, when executed by the function execution unit, causes a scroll of the image.   
     
     
         3 . The information display device according to  claim 1 , wherein
 the predetermined function is a scale change function which, when executed by the function execution unit, changes a scale of the image.   
     
     
         4 . The information display device according to  claim 2 , wherein
 the control parameter is a scroll movement amount of the image responsive to the drag operation; and   the function control unit is configured to increase the scroll movement amount as the number of touched points as determined by the touched-point number determination unit increases.   
     
     
         5 . The information display device according to  claim 3 , wherein
 the control parameter is a scale change amount responsive to the drag operation; and   the function control unit is configured to increase the scale change amount as the number of touched points as determined by the touched-point number determination unit increases.   
     
     
         6 . The information display device according to  claim 1 , wherein
 if the number of touched points as determined by the touched-point number determination unit is two or more, the function control unit is configured to inhibit a change of the control parameter of the predetermined function based on a spatial relationship of the respective touched points.   
     
     
         7 . The information display device according to  claim 2 , wherein,
 the control parameter is a scroll movement amount of the image responsive to the drag operation; and   if the number of touched points as determined by the touched-point number determination unit is two or more, the function control unit is configured to inhibit a change of the scroll movement amount of the scroll function based on a spatial relationship of the respective touched points.   
     
     
         8 . The information display device according to  claim 3 , wherein
 the control parameter is a scale change amount responsive to the drag operation; and   if the number of touched points as determined by the touched-point number determination unit is two or more, the function control unit is configured to inhibit a change of the scale change amount of the scale change function based on a spatial relationship of the respective touched points.   
     
     
         9 . The information display device according to  claim 4 , wherein
 if the number of touched points as determined by the touched-point number determination unit is two or more, the function control unit is configured to inhibit a change of the scroll movement amount of the scroll function based on a spatial relationship of the respective touched points.   
     
     
         10 . The information display device according to  claim 5 , wherein
 if the number of touched points as determined by the touched-point number determination unit is two or more, the function control unit is configured to inhibit a change of the scale change amount of the scale change function based on a spatial relationship of the respective touched points.   
     
     
         11 . The information display device according to  claim 6 , wherein
 if the number of touched points as determined by the touched-point number determination unit is two or more and positions of the respective touched points are separated by a predetermined distance or more, the function control unit is configured to not change the control parameter of the predetermined function.   
     
     
         12 . The information display device according to  claim 6 , wherein
 if the number of touched points as determined by the touched-point number determination unit is two or more and movement directions of the respective touched points are different, the function control unit is configured to not change the control parameter of the predetermined function.   
     
     
         13 . The information display device according to  claim 6 , wherein
 if the number of touched points as determined by the touched-point number determination unit is two or more and a difference in movement speed between the respective touched points is a predetermined speed or more, the function control unit is configured to not change the control parameter of the predetermined function.   
     
     
         14 . A method of performing a predetermined function by an information display device in response to a drag operation on a touch panel of the information display device, said method comprising:
 determining a number of touched points in the drag operation as detected by the touch panel; and   executing the predetermined function differently depending on the determined number of touched points.   
     
     
         15 . The method according to  claim 14 , further comprising
 changing a control parameter of the predetermined function according to the determined number of touched points; and   executing the predetermined function in accordance with the changed control parameter.   
     
     
         16 . The method according to  claim 15 , wherein
 the control parameter is increased when the determined number of touched points increases.   
     
     
         17 . The method according to  claim 15 , further comprising
 if the determined number of touched points is two or more, inhibiting a change of the control parameter based on a spatial relationship of the respective touched points.   
     
     
         18 . The method according to  claim 17 , wherein said inhibiting is performed in response to one or more of the following:
 positions of the respective touched points are separated by a predetermined distance or more,   movement directions of the respective touched points are different, or   a difference in movement speed between the respective touched points is a predetermined speed or more.   
     
     
         19 . The method according to  claim 15 , further comprising
 changing said control parameter in response to a change in the determined number of touched points during the drag operation.   
     
     
         20 . A computer-readable medium containing a program for causing, when executed by a central processing unit of an information display device computer, the central processing unit to execute, in response to a drag operation on a touch panel of the information display device, a predetermined function differently depending on a number of touched points in said drag operation.